Self-lubricating hinge pin



March 4, 1952 M. DE GRAAF SELF-LUBRICATING HINGE PIN Filed March 26, 1949 3nventor DEGRAAF' MAURICE attorney Patented Mar. 4, 1952 UNITED STATES PATENT OF F ICE SELF-LUBRICATING HINGE rm Maurice De Graaf, Grand Rapids, Mich. Application March 26, 1949, Serial No. 83,588 1 Claim. (01. 16-151) This invention relates to hinges and more particularly to a hinge pin having a permanent source of lubrication.

Although the design and construction of hinges is an exceedingly ancient art, antedating even mans knowledge of metal, throughout this entire period the designers and users of hinges have failed to solve the problem of permanently preventing these hinges from squeaking. The method, now employed, of periodically lubricating the hinge is not a satisfactory solution. It is necessary to repeat the lubricating process at various intervals and it is a tedious and inconvenient job. Particularly is this true where the hinges are painted or otherwise coated to hide them, since the spilling of the lubricant will both stain and ultimately decompose the paint. To avoid getting lubricant on the exterior of the hinge, it is necessary to remove the pin, lubricate it, and reinsert it. This is a long and unpleasant job, particularly when the pins are diflicult to remove.

My invention renders this repeated lubrication unnecessary by providing a simple hinge pin having a substantially permanent internal source of lubrication. The lubricant seeps outwardly to the surface of the pin throughout the life of the hinge. The amount of lubricant present at any one time is insufficient to cause seepage between the joints of the hinge. Damage to paint or varnish with which the hinge may be coated is eliminated.

It is, therefore, a primary object of my invention to provide a hinge pin having a substantially permanent internal source of lubrication.

It is a further object of my invention to provide a hinge pin capable of lubricating the hinge throughout the life of the hinge.

It is an additional object of my invention to provide a hinge pin which will be durable, yet simple and economical to fabricate.

Other objects and purposes of my invention will be seen by those acquainted with the art of hardware construction upon reading the following specification and the accompanying drawings.

In the drawings:

Figure 1 is a side elevation view of my improved hinge pin.

Figure 2 is a fragmentary sectional elevation view of my improved hinge pin taken along the plane II--II of Figure 1.

Figure 3 is a sectional view of my improved hinge pin taken along the plane III-III of Figure 1.

Figure 4 is a fragmentary elevation View of a hinge equipped with my improved hinge pin.

Fi ure 15 is a side elevation View of a modification of my improved hinge pin.

In executing th objects and purpcses ofmy invention, I have provided a hinge pin having a knobpfstandard construction and a rod of circular cross section made from steel or other suitable metal. The rod is surrounded by a .bushins impre nated with amb e tcapeb e of-slow- 1v o i g from he bu hin ever a lens p i of time.

Referring now specifically to the drawings, the numeral I indicates a pin having a head 2 and a shank 3. The head 2 may have any convenient shape such as that shown in which a flange 4 projects radially outwardly from the base of a knob 5. The head 2 is provided with an internal threaded opening 6 into which is mounted the threaded end of the core member 1 of the shank 3. The core I consists of a solid rod of circular cross section having a length substantially equal to the height of the hinge. The core member 1 has a sufliciently small diameter that the hereinafter described bushing 8, designed with a substantial wall thickness, will not have an exterior diameter in excess of hinge pins of standard construction.

The head 2 and the core member 1 may be made from any suitable material such as cast iron, steel or brass. The core I and the head 2 may be joined in any suitable manner such as by the threading illustrated in Figure 2 or by a swaged union. It is also possible to make them as an integral piece without in any way chang ing the principle of my invention.

The core fl is surrounded by a bushing 8 having an external diameter equal to that of pins of standard construction for the particular size hinge for which it is intended. The bushing 8 consists of a wear resistant, porous material, such as that obtainable in certain bronzes and porous types of iron, having each of its interstices filled with a lubricant. The interior opening of the bushing 8 has a diameter of such size that it frictionally grips the core member 1. It is pushed axially along the core, member 1 until it seats against the head 2 and thereafter is locked into position by a head such as one formed by peening the end of the core member I to form the button 9. The button 9 prevents displacement of the bushing 8 longitudinally of the hinge pin l.

The hinge pin I, once installed, continuously oozes a minute quantity of lubricant to coat its exterior surface. This lubricant provides a shield between the hinge housing If] and the hinge pin i.

Thus, the hinge will be continuously lubricated with a controlled quantity of lubricant, which quantity will be efiective to prevent wear and noise but sufiiciently limited to prevent seepage between the joints ll of the hinge housing H! where it could cause discoloration or peeling of paint or varnish. The use of the bronze bushing will, without the lubricant, reduce wear on the hinge due to the wear resistant character of the bronze itself. The presence of the lubricant will further prevent wear, thus eliminating looseness between the hinge housing In and the pin I resulting from frequent use. At the same time the lubricant will prevent the hinge from squeaking. Thus, there is provided a durable hinge pin requiring no lubrication servicing throughout the life of the hinge.

In Figure 5 is shown a modification of my hinge pin in which the bushing 8 consists of a number of short lengths 8a mounted coaxially on the core member la and held in place by a button 9a. The purpose of dividing the bushing 8 into a number of short lengths 8a is to obtain the economy available in the shorter length of bushings of this type. However, a hinge pin so constructed will function in a manner identical with that shown in Figure 1.

Other modifications and uses of my invention will be seen by those acquainted with articles of 4 this type. However, each of such modifications are to be considered as included within the scope of the following claim unless such claim by its wording expressly provides otherwise.

I claim:

In a hinge construction including a central pivot pin, the improvement in said pin comprising: a core member of circular cross section; a bushing comprising a plurality of sections, said sections together having a length equal to the length of said core member; said bushing being of porous material and mounted on and surrounding said core member; said bushing being of constant diameter throughout its length and impregnated with a lubricant, whereby said lubricant While said pin is in use will be gradually released by said bushing for coating the surface of said bushing; head means on each of the ends of said pin.

MAURICE DE GRAAF.

REFERENCES CITED UNITED STATES PATENTS Name Date Roth Sept. 10, 1940 Number 

